Is Your Onyx Jewelry Real? Identifying Genuine Onyx

Question
I have a "onyx" brooch/ pin and matching earrings. The onyx is framed and smooth  (does not stick out over the frame. The earrings are the same and say pat pending . The earrings are very small clip ons. Its Brass or Bronze I think, In your opinion is this just costume and not a real onyx?  THanks for your time

Answer
Theresa, I have seen both genuine onyx and plastic and glass stones in earrings and brooch like you mentioned.  I suspect the back is covered so you cannot see the back of the stone. If by good chance you can see the back of the stone, look for a smooth surface with some grind or sanding marks on it for genuine. Look for a glassy look and perhaps an uneven surface for glass, a molded look. Shine a light through the stone and see if any light passes to the front. Glass will have a glass look and perhaps swirls in the pattern like thick sugar syrup over a double boiler. Onyx will either not pass the light at all or will have little pattern.  These tests are not the last word at all but will provide some clues.

Generally, the stones in older or antique jewelry like this with brass mountings are glass.

I do hope this will help some. God Bless. Thomas.
Nov. 7,2007  7:02pm